c# - MongoDB 的存储库模式 : Where to initialize the Database

Question

我刚开始使用 MongoDB (C#) 并尝试从 Entity Framework 移植一个存储库。我正在使用官方 C# 驱动程序 1.0。现在我做了这样的事情:

internal class MongoContext
{
    public MongoContext(string constring)
    {
        MongoServer server = MongoServer.Create(constring);
        this.myDB = server.GetDatabase("MyDB");

        BsonClassMap.RegisterClassMap<VoyageNumber>(cm =>
            { cm.MapField<string>(p => p.Id); });
        BsonClassMap.RegisterClassMap<Schedule>(cm =>
        { cm.MapField<DateTime>(p => p.EndDate); cm.MapField<DateTime>(p => p.StartDate); });
        BsonClassMap.RegisterClassMap<Voyage>(cm =>
            { cm.MapIdField<VoyageNumber>(p => p.VoyageNumber); cm.MapField<Schedule>(p => p.Schedule); });

    }

    private MongoDatabase myDB;
    public MongoDatabase MyDB
    { get { return this.myDB; } }
}

然后我会继续像这样实现存储库:

public class MongoVoyageRepository : IVoyageRepository
{
    private readonly MongoContext context;

    public MongoVoyageRepository(string constring)
    {
        this.context = new MongoContext(constring);
    }

    public void Store(Domain.Model.Voyages.Voyage voyage)
    {

        MongoCollection<Voyage> mongoVoyages = context.MyDB.GetCollection<Voyage>("Voyages");

        //store logic...

    }

}

现在我想知道在性能方面实例化这样的“上下文”是否是一个好的决定。将 BsonClass 映射放在那里有意义吗？感谢您的输入。

Answer 1

// entity base
public class MongoEntity {
    public ObjectId _id { get; set; }
}

//user entity
public class Users : MongoEntity {
    public string UserName { get; set; }
    public string Password { get; set; }
}


// simple repository
public class Repository {

    private MongoDatabase _db;
    public MongoDatabase Database { get; private set; }
    public Repository(string constr, string dbname) {
        var server = MongoServer.Create(constr);
        _db = server.GetDatabase(dbname);
        Database = _db;
    }

    private MongoCollection<T> GetCollection<T>() where T : MongoEntity {
        return _db.GetCollection<T>(typeof(T).Name);
    }

    public IEnumerable<T> List<T>() where T : MongoEntity {
        return GetCollection<T>().FindAll();
    }

    public IEnumerable<T> List<T>(Expression<Func<T, bool>> exp) where T : MongoEntity {
        return GetCollection<T>().AsQueryable<T>().Where(exp);
    }

    public T Single<T>(Expression<Func<T, bool>> exp) where T : MongoEntity {
        return List<T>(exp).SingleOrDefault();
    }

    public void Insert<T>(T entity) where T : MongoEntity {
        GetCollection<T>().Insert<T>(entity);
    }

    public void Insert<T>(ICollection<T> entities) where T : MongoEntity {
        GetCollection<T>().InsertBatch(entities);
    }

    // Update, Delete method etc ...



}



// example
var repository = new Repository("mongodb://localhost", "test");
repository.Single<Users>(u => u.UserName == "myUserName");